Salts of alpha-sulfonated fatty acid esters



United States Patent "ice 3,128,294 SALTS OF a-SULFONATED FATTY ACID ESTERS Alexander J. Stirton and Raymond G. Eistline, .112, Philadelphia, James K. Weil, North Wales, and Waldo C. Ault, Glenside, Pa., assignors to the United States of America as represented by the Secretary of Agriculture No Drawing. Original application June 9, 1961, $121. No. 117,491. Divided and this application June 21, 1962, Ser. No. 210,281

16 Claims. (Cl. 260400) (Granted under Title 35, U.S. Code (1952), see. 266) A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

This application is a division of Serial No. 117,491, filed June 9, 1961.

This invention relates to highly efiicient Wetting agents which are salts of esters of a-sulfonated fatty acids, to surface active compositions containing one or more of these wetting agents as an essential component, and to synergistic combinations containing these wetting agents.

An object of this invention is to provide Wetting agents having a wetting time in the Draves test of less than seconds, preferably less than six seconds. Another object is to provide wetting agents which have good solubility in both water and in oil. A further object is to provide improved wetting agents which exhibit stability under acidic or alkaline conditions, even at elevated temperatures. Other objects and a better understanding of the invention may be had by referring to the following description and claims.

The Wetting agents of the present invention may be represented by the general formula RCH(SO M COOR' where R is a normal alkyl radical containing 2 to 12 carbon atoms, M is sodium, potassium or ammonium, and R is a normal primary, branched chain primary, normal secondary, or branched chain secondary alkyl group containing 2 to 15 carbon atoms or the H(CF C-F CH group, and the sum of the carbon atoms in R plus R plus 2 is an integer from 14 to 19, inclusive. Expressed in another manner, the Wetting agents are the sodium, potassium or ammonium salts of alkyl or fiuoroalkyl esters of a-sulfo fatty acids.

As will be subsequently demonstrated in referring to the tabulated data, there are certain limitations as to the fatty acid or the alcohol which may be incorporated into the compounds of this invention, and especially in regard to the particular combinations of acids and alcohols. The fatty acid is limited to a normal saturated fatty acid containing from 4 to 14 carbon atoms, that is, butyric to myrstic acids, inclusive. A large number of individual compounds are included in the scope of the general formula, however, because of the combinations obtainable in varying the alcohols and acids which are combined to form the esters. In the case of esters of a-sulfopelargon-ic acid, for example, the alcohol may be n-amyl, hexyl, heptyl, octyl, nonyl, decyl, or capryl (C H CHOHCH alcohol, 2-cthylhexanol, branched chain decyl alcohols, or dodecafluoroheptyl alcohol (H(CF CF CH OH). The

3,128,294 Patented Apr. 7, 1964 compounds in Table I are presented to further illustrate some of the wetting agents of the present invention.

TABLE I Wetting Agents, RCH(SO M) CO R [R+R'|-2=14l9] While most of the compounds are sodium. salts, the most practical form cost-wise, these wetting agents may be prepared as potassium or ammonium salts if desired.

The wetting agents of our invention are characterized by very low wetting time values in standard tests used for the evaluation of wetting agents such as the Braves test using a cotton skein (Am. Dye-stuff Reptr. 23, 425 (1939)), the Seyferth and Morgan canvas disk method (Am. Dyestuif Reptr. 27, 525 (1938) or the Shapiro binding tape method (Am. Dyestuif Reptr. 39, 38 (1950)). The wetting agents of our invention at a concentration of 0.1% in aqueous solution have a wetting time value in the Braves test ranging from zero (or instantaneous wetting) to about 10 seconds, usually 6 seconds or less.

This very rapid wetting characteristic of the wetting agents of our invention is unexpected in view of the fact that the only recorded values for salts of alkyl esters of wsulfonated fatty acids range from 18 to 43 seconds at 0.1% concentration by the binding tape method (Stirton, Well and Bistline, I. Am. Oil Chemists Soc. 31, 13 1954) The wetting agents of our invention are further characterized by many desirable and useful properties. They are easily soluble in water, ethanol, ethyl ether, chloroform, paraffin oil and lubricating oil. They have low surface and interf-acial tension, adequate calcium stability in many cases and are useful in hard water. An outstanding advantage in contrast to present commercial wetting agents of the ester type, is the fact that they are not easily bydrolyzed and have wetting properties even in hot acid or alkaline solutions. Stability to hydrolysis arises from protection of the carboxylic acid ester group by the adjacent a-sulfo group through steric hindrance.

The highly eihcient wetting agents of our invention are also characterized by critical micelle concentration (c.m.c.) values'in the range 0.5-16.0 millimolca/ 1. For a given homologous series, such as the pelargonates, the

most efiicient members demonstrate correlation between low surface and irrterfia-cial tension, c.m.c, and low Wetting time values.

The Wetting agents of our invention need not be chemically pure individual compounds in order to be useful. Thus, mixtures of two or more of the salts of esters of a-sulfonated fatty acids of Table I constitute effective wetting agents. Furthermore we have discovered that a commercial fatty acid mixture can be used in place of a chemically pure fatty acid. Thus a product based on coconut oil fatty acid foreruns and 2-ethylhexanol is an efiicient wetting agent. In this case the coconut oil fatty acid forerun is a mixture of caproic, caprylic, capric, lauric and myristic acids which has an average composition approximating that of decanoic acid. A representative formula for the salt of the ester of the a-sulfonated fatty acid mixture is CgH17cH(SO3N3.)CO2C H17 where the total number of carbon atoms R+R'+2 in the formula is 8+8+2 or 18, in agreement with the scope of our invention.

Another object of our invention is to provide mixtures of individual esters which are synergistic in behavior. Sodium alkyl a-sulfopalmitates and sodium alkyl a-SlllfO- stearates do not have pronounced wetting properties but we have discovered that mixtures of these or of sodium salts of alkyl esters of a-sulfonated tallow acids with the wetting agents of our invention have wetting properties superior to the contribution of either ester alone. Thus a mixture of 0.05% each of sodium alkyl oz-sulfopelargonate and sodium alkyl u-sulfostearate has a lower wetting time than the sum of the time for the two surface active agents alone at 0.05% concentration, or the average for the two surface active agents at 0.1% concentration. This synergism is particularly evident in hard Water.

Synergism need not derive from a simple mixture of two chemically pure sodium salts of alkyl esters of a-sulfonated acids but may derive from readily available industrial fatty acids such as a combination of hydrogenated coconut oil fatty acids with hydrogenated tallow fatty acids. Thus a mixture of hydrogenated coconut oil fatty acids and hydrogenated tallow fatty acids is sulfonated with the vapor of sulfur trioxide, esterified with secondary butyl alcohol and neutralized to form the sodium salt of the butyl esters of the ot-sulfonated fatty acids.

Another object of our invention is to provide improved wetting agent compositions particularly useful in Very hard water and in the presence of various metal ions. We have discovered that certain wetting agents of our invention which are not quite as useful in hard as in soft water can be improved by the presence of a builder such as sodium or potassium pyrophosphate or tripolyphosphate, or by the presence of a sequestrant to a remarkable extent. The improvement is synergistic and it is possible to obtain superior wetting properties even at lower concentrations of the active ingredient as shown by the data for sodium alkyl u-sulfopelargonates in Table VI.

The wetting agents of our invention are highly efficient, stable to hydrolysis, useful in hard water and easily soluble in water. They are also easily soluble in ethanol, ethyl ether, chloroform, petroleum ether, paraflin oil and lubricating oil and are thus useful in non-aqueous systems as well, as insecticidal sprays, industrial emulsifying agents and addition agents to lubricants.

The wetting agents of our invention are useful with soap and other detergents in hard water, suitably in synergistic mixtures with builders such as pyrophosphates and tripolyphosphates.

The wetting agents of our invention may be prepared by a variety of methods. The method may be selected on the basis of the particular structure desired. Thus an ester of the general formula RCH(SO M)CO R where R is C H s, M is K and R is C H specifically potassium butyl a-sulfomyristate (Table I) may be prepared by the reaction of a-sulfomyristic acid with butyl alcohol and neutralization by potassium hydroxide or potassium carbonate;

or precipitation and separation by addition of inorganic potassium salts. No esterification catalyst is required because the sulfonic acid group of u-sulfomyristic acid constitutes the esterification catalyst.

Esters of Ot-SlllfO acids and alcohols of nearly equal chain length such as sodium hexyl u-sulfopelargonate (Table I) can be prepared by the reaction of sodium a-sulfopelargonic acid with hexyl alcohol, catalyzed by sulfuric acid, in the presence of benzene, toluene or xylene to remove water of esterification azeotropically.

Esters of shorter chain u-sulfo acids and longer chain fatty alcohols, for example sodium decyl a-sulfocaproate (Table I) may be prepared by the reaction of u-sulfocaproic acid with decanol. The a-sulfocaproic acid formed by the reaction of caproic acid with sulfur trioxide, need not be isolated. Decanol may be added to the sulfonation reaction mixture with an aromatic hydrocarbon included to remove water of esterification azeotropically. On completion of the reaction the mixture is neutralized with aqueous NaOH or the sodium salt of the desired ester is precipitated by addition of an inorganic sodium salt.

Other means for the formation of the esters of our invention include the reaction of the barium salt of an asulfo fatty acid, from butyric to myristic acid, with an alcohol of the requisite number of carbon atoms, in the presence of an aromatic hydrocarbon to remove Water of esterification azeotropically, and in the presence of a slight excess of sulfuric acid. The barium sulfate precipitated is removed and the ester can be isolated as the Na, K or NH, salt. Still another means is the replacement of a halogen atom in the ester RCHXCO R by means of an inorganic sulfite. The following examples illustrate but do not limit the nature and scope of our invention.

EXAMPLE 1 Sodium Hexyl a-Sulfopelargonate A 500 ml. round bottom 3-neck flask was charged with 25 grams of sodium oc-sulfopelargonic acid, 38 ml. of nhexanol, 200 ml. of toluene and 2 ml. of concentrated sulfuric acid. The stirred mixture was refluxed 4 hours with azeotropic removal of water, neutralized with sodium carbonate and evaporated with recovery of solvent and excess hexanol. Ethanol was added to the residue, inorganic salts were removed, and the product was recrystallized from 50% ethanol at 20 C. to give sodium hexyl ot-sulfopelargonate in 86% yield. Final recrystallization gave the pure ester.

Analysis.Calculated for C H NaO S: 6.68% Na, 9.31% S; found 6.59% Na, 8.95% S.

The sodium a-sulfopelargonic acid can be prepared by the sulfonation of pelargonic acid with liquid sulfur trioxide in the presence of carbon tetrachloride as the solvent, or by sulfonation With sulfur trioxide vapor in the absence of solvent as described in our publication [Weil, Stirton, Bistline, Ir., and Ault, J. Am. Oil Chemists Soc. 37, 679- 682 1960)].

EXAMPLE 2 Sodium Capryl a-Sulfopelargonaze Sodium a-sulfopelargonic acid Was esterified with capryl alcohol (octanol-Z) after the manner of Example 1. Sodium capryl a-sulfopelargonate was isolated in a pure state in a yield of 65%.

Analysis.Calculated for C H NaO S: 54.81% C, 8.93% H, 6.17% Na, 8.61% S; found 54.37% C, 9.19%. H, 6.07% Na, 8.79% S.

EXAMPLE 3 Sodium Nonyl wSulfopelargonute Esterification of sodium u-sufopelargonic acid with nnonanol after the manner of Example 1 gave sodium nonyl u-sulfopelargonate in a pure state in a yield of 70%.

Analysis.-Calculated for C H NaO S: 5.95% Na, 8.30% S; found 5.82% Na, 8.24% S.

EXAMPLE 4 Sodium x0 Decyl a-Sulfopelargonate A commercial decyl alcohol from the oxo process (a mixture of isomeric 10- carbon atom primary alcohols, predominantly isomeric trimethylheptanols) was esterified with sodium a-sulfopelargonic acid after the manner of Example 1. Sodium. oxo decyl u-sulfopelargonate was obtained as a light yellow product.

Analysis.-Calculated for C H NaO S: 5.74% Na; found 5.80% Na.

EXAMPLE 5 Sodium a-sulfopelargonic acid was esterified with 1H, 1H,7H-dodeca:fluoro-l hepanol [H(CF CF CH OI-L] in a manner similar to Example 1. The product ester was a white solid.

Analysis.-Calculated for C H CH(SO Na)CO CI-I (OF CF H 4.00% Na; found 3.98% Na.

EXAMPLE 6 Sodium Amyl a-Sulfolaurate a-Sulfolauric acid was prepared by vaporizing 60 ml. of liquid sulfur trioxide and leading the vapor mixed with nitrogen into a stir-red solution of 202 g. of lauric acid in 250 ml. of chloroform and 250 ml. of carbon tetrachloride during 3- hrs. at- 30-45 C. The sulfonation mixture was further heated to 60 C., refrigerated at --20 C., filtered and dried over calcium sulfate. a-Sulfolauric acid was obtained as, a gray solid.

Analysis-Calculated for C H NaO S: neutralization equivalent (N.E.) 140.2; found 134.2. A portion was converted to the monosodium salt by means of sodium chloride.

Analysis.-Calculated for C H NaO S: 7.60% Na, N.E. 302.4; found 7.55% Na, N.E. 302.3.

A mixture of 28 grams of oz-SlllfOhUliC acid, 11.5 ml. of n-amyl alcohol and 200 ml. of toluene was heated and stirred for 2.5 hours at the reflux temperature with azeotropic removal of water. The reaction mixture was neutralized with aqueous sodium hydroxide and evaporated with recovery of toluene and excess n-amyl alcohol. The residue was treated with absolute ethanol, inorganic salts were removed, water was added and the product was crystallized from aqueous ethanol at 20 C. to give sodium amyl a-sulfolaurate.

Analysis.--Calculated for C H NaO S: 6.17% Na; found 5.98% Na.

EXAMPLE 7 Potassium Butyl u-Sulfomyristate EXAMPLE 8 Sodium Dodecyl a-Sulfobutyrate The barium salt of a-sulfobutyric acid S-O O t CHaCHaCH 6 was prepared by the sulfonation of butyric acid with sulfur trioxide and the isolation of the product as the barium salt.

Analysis.Calculated for C H BaO S: 45.26% Ba; found 45 26% Ba.

A stirred mixture of 0.1 mole (30.4 g.) of barium asulfobutyrate, 0.11 mole (20.4 g.) of dodecanol, 11 g. of concentrated H SO and 200 ml. of toluene were refluxed 3 hours with azeotropic removal of water and neutralized with alcoholic NaOH. After removal of BaSO by filtration, and unreacted dodecanol by ether extraction of an aqueous alcohol solution, the extracted solution was evaporated to give a 63% yield of sodium dodecyl a-sulfobutyrate.

Analysis.-Calculated for C H NaO S; 6.42% Na; found 6.27% Na.

EXAMPLE 9 Sodium Salt of Z-Ethylhexyl Ester of a-Sulfonated Coconut Oil Fatty Acid Forerun A commercial coconut oil fatty acid forerun was used (a mixture of about 42% caprylic, 28% capric, 24% lauric and 6% myristic acid, neutralization equivalent 169.3), corresponding to decanoic acid on the average.

Sulfur trioxide vapor mixed with nitrogen, containing grams (1.12 moles) of sulfur trioxide was passed into the semi-liquid coconut oil fatty acid forerun, 161 grams (0.95 mole), at 14 C., with agitation. The temperature of the viscous reaction mixture reached a maximum of 64 C. Toluene and 2-ethylhexanol were added and the sulfonated fatty acids were esterified with azeot-ropic removal of water. The reaction mixture was neutralized with sodium hydroxide and the product was isolated after recovery of solvent as the sodium salt of the 2-ethylhexyl ester of a-sulfonated coconut oil fatty acid foreruns.

Analysis.Calculated for C H NaO S: 5.95% Na; found 6.44% Na. The product may contain about 8% inorganic salts.

PROPERTIES The surface active and related properties of the wetting agents of our invention are illustrated in Table II. With the exception of compounds included for comparison, all of the compounds listed are wetting agents which come within the scope of our invention. The compounds included for comparison are potassium hexadecyl a-sulfopropionate, sodium ethyl and dodecyl a-sulfopelargonate, sodium methyl and dodecyl a-sulfolaurate, and sodium methyl a-sulfopalmitate.

The wetting agents of our invention listed in Table II have wetting times by the Draves test (0.1% solution, 5 g. cotton skein, 3 g. hook, 40 g. anchor) of 6 seconds or less. They may be more efiicient in soft than in hard water, or more eflicient in hard water or may be about equally eflicient in soft and hard water. The most efficient of Table II are characterized by low surface and interfacial tension and a critical micelle concentration in the range of about 1-7 millimoles/l. These are sodium dodecyl a-sulfobutyrate, sodium hexyl, heptyl, capryl, and 2-ethylhexyl asulfopelargonate, sodium 2-ethylhexyl a-sulfo coconut oil fatty acid forerun, sodium propyl, butyl and amyl a-sulfolaurate and potassium butyl a-sulfomyristate.

The calcium stability ranges from about 300 to 1800 ppm. calculated as calcium carbonate, and so all of the wetting agents are useful, with different degrees of efliciency, in hard water of the degree of hardness normally encountered; and a few are useful in the presence of very large concentrations of the calcium ion.

The most efficient wetting agents of Table II have excellent foaming properties in either soft or hard water and give a stable and attractive foam. Although excellent wetting characteristics are usually associated with rather mediocre detergent properties several of the wetting agents of our invention have good detergency as well as excellent wetting characteristics.

TABLE II Properties of Wetting Agents Surface and Wetting Time. Interfacial Ten- Draves test 0.1% Foam, 60 0., Detergency Alcohol R OH sion, dynes/ O.M.C.= solution, seconds Ca++ 0.25% solu- Launder cm., 0.2% solns. millimolcs stability tions, mm. Ometer,

per liter p.p.m. 0.25%

solutions SIP. LT. Distd. 300 Distd. 300 60 0., AR

p.p.m. p.p.n1.

K Hexadccyl a-suliopropionate. 35. 5. 3 .2 58.0 300 480 Na Dodecyl a-Sulfobutyrata 36. 8 9. 1 1. 9 5. 5 4. 4 1, 800 200 225 27 Na Alkyl a-sulio-Pelargonatcsz 0H 52. 9 39.8 98. 0 300 300 1, 800 4 0 CnHuOIL. 40. 3 18. 9 16.0 12.1 5. 3 3 80 140 CoHraOEL. 26. 8 7. 1 7. 0 2. 2 1. 4 290 210 240 23 0 111 011 26. 6 5. 7 4. 5 1. 5 4. 7 440 210 2A0 26 0811170 25. 7 4. 5 2. 1 1. 3 13. 2 500 230 220 31 CoHlaCHOHCHa 26. 4 4. 8 3. 6 1. 3 4. 5 520 220 230 25 BuCHBtCHrOH 25. 9 3. 9 1.9 0.0 4. 5 530 240 175 17 91110 25. 4 3. 8 1. 2 3.8 33.1 500 230 80 31 0101121011-... 25.0 3.0 0.5 6.0 105.0 610 240 30 21 Ox0" Decyl 23. 6 1. 7 0.5 1.6 34.8 310 250 19 C1zHz50H 25.2 1. 0 0.1 103. 0 300 750 210 20 26 H(CF2CF2)3CH;OH. 19.1 5. 6 2. 4 3. 6 24. 8 350 265 30 20 Na Alkyl 11.-Sl1lf0 Coconut Oil Fatty Acid Forerun: BuCHEtOHgOH. 25.3 1.5 3.5 5.5 500 220 150 Na Alkyl a-Suliolaurates:

CH3OH 28. 3 11.1 57. 6 34. 3 1, 800 170 210 16 CzHsOH..- 31.9 7. 9 10. 5 5. 4 1, 800 130 210 22 Cal-170E 35. 5 9. 5 3.2 2.0 1, 800 210 230 25 CiHcOH 33. 8 8.7 1. 6 1. 5 220 230 24 C H1|OH 31.1 6. 9 1. 6 4. 9 500 220 235 26 C0H13OII 28.1 4.6 2. 2 39. 5 570 230 180 23 CwHuOH 25.6 3. 8 300 300 140 20 30 KAlkyl a-Sulfo-Myristates: C4H0OH- 31.6 4. 5 4. 8 5. 2 500 215 240 32 Na Alkyl a-Sulfo-Palmitates: OH3OH 39.0 9. 7 25.0 15. 5 1, 800 205 225 31 Critical micelle concentration. AR=increasc in reflectance after washing; AR for 0.25% Na dodccyl sulfate in distd. water=28.0.

WETTING TIME AND lCONCEN'DRATION TABLE IV The Wetting time of 6 of the most eflicient wetting agents of our invention was measured by the Draves test (5 g. cotton skein, 3 g. hook) at concentrations from 0.025% to 0.15% in distilled water, in comparison with the highly efiicient commercial wetting agent, sodium di(2-ethylhexyl) sulfosuccinate. The results are shown in Table III.

It is evident the wetting agents listed equal or exceed the efliciency of the commercial wetting agent at almost every concentration. They have a decided advantage in that unlike sulfosuccinate wetting agents they are quite stable and are not easily hydrolyzed even in hot acid or alkaline solutions; accordingly they are more useful in commercial processes.

STABILITY TO HYDROLY-SIS In Table IV the rate of hydrolysis of esters of ot-sulfo fatty acids is compared with that for the commercial wetting agent, sodium di(2-ethylhexyl) sulfosuccinate.

TABLE III Wetting Time and Concentration Wetting time, seconds, solutions in distilled water, Draves test, at various Wetting Agent Wetting agent concentrations Sodium heptyl a-sulfopelargonate Sodium octyl a-sulfopelargonate Sodium capryl wsulfopelargonate Sodium 2-ethylhexyl a-sulfopelargonate Sodium butyl a-sultolaurate. Sodium amyl a-Sulfolaurate. Sodium di(2ethy1hexyl) sullosuccinate 1 1 Commercial wetting agent. 3 Instantaneous.

Rate Constants, Acid and Alkaline Hydrolysis k1(N/3 n,so. =1 l in i minutes" 100 0.

Acid catalyzed hydrolysis, heating 0.1 gram equivalent =at 100 C. in the presence of N/ 3 H was found to be a first order reaction. {The a-sulfo group protects the adjacent carboxylic acid ester group through steric hindrance. The sulfosucoinate ester was found to have 2 reaction rate constants in acid catalyzed hydrolysis. Hydrolysis takes place rapidly at first at the {3 ester linkage CH CO CH CH(C H )C H of the sulfosuccinate 9; since this is unprotected by an adjacent sulfo group. The reaction rate constant, k (fi)=0.0156. All wetting properties were lost in this initial stage of hydrolysis. Hydrolysis at the ester group adjacent to the sulio group then proceeded at a much slower rate, k (m)=0.0033, comparable to the value for sodium hexyl u-sulfopelargonate, k =0.0020, and sodium methyl a-sulfopalmitate, k =0.0047. Sodium capryl u-sulfopelargonate, an ester of a secondary alcohol, hydrolyzed at the slowest rate, k =0.0010. Comparative rates are shown in Table IV.

Alkaline hydrolysis is a second order reaction. Under these conditions hydrolysis of the sulfosucoinate was too rapid to measure in separate stages; accordingly a reaction rate at the midpoint of hydrolysis, k =0.9, was taken and rates were expressed relative to this value. Sodium capryl u-sul-fopelargonate, an ester of a secondary alcohol, is seen to be especially resistant to either acid to alkaline hydrolysis.

In Table V the wetting time [601' sodium capryl oc-Slllfopelangonate, sodium heptyl ot-sul-fopelargonate, and sodium di(2-ethylhexyl) sulfosuccinate is compared, in

TABLE V Stability to Hydrolysis.

heptyl a-sulfopelargonate retained its wetting properties in boiling 5% H 80 solution, and sodium capryl a-sulfopelar'gonate continued to have good Wetting properties in hot acid solution and in hot 1% NaOH solution as well. This stability to hydroulysis increases the field of usefulness tor the wetting agents of our invention.

SYNERGIS-IIIC COMPOSITIONS {Iable VI demonstrates that the wetting agents of our invention, particularly those which are not as eflicient in hard as in soft water, are improved by the presence of a builder which in the particular data cited is a mixture of 56% sodium tripolyphosphate, 24% sodium suliiate, 10% sodium pyrophosphate, and- 10%. sodium metasilicate. The improvement is synergistic and is beyond that to be expected or predicted.

Synergism in mixtures of sodium alkyl a-sulfopelargomates with builders is shown in the fact that in hard water the wetting time for the octyl, nonyl and decyl esters at 0.05% concentration (21.2, 40. 8, 130.0 seconds) is reduced to 5.0, 13.6, 43.3 seconds respectively; at 0.10% concentration (13.2, 33.1, 105.0 seconds) to 4.0, 8.2, 31.6 seconds, respectively; and particularly by the fact Wetting Properties in Acid and Alkalz Wetting Time, seconds, Draves Test, 5 g. skein, 3 g.hook, 0.1% concentration, 25 C.

' Boiled In- Boiled In Surface Active Agent Distd. 5% 1% Water E2804 5% for H SO; NaOH 1%.ior NaQH 36 for V for Hour lHour Hour lHour Sodium Methyl a-Suliopolmitate 25.0 28.2 36.8 36.5 36.8 600 Sodium capryl u-sultopelargonate 1. 3 3. 5 5. 8 6. 6 4.4 8.0 21. 2 Sodium Heptyl a-Suliopelargonate 0.0 3.0 4.1 4.5 3.4 600 Sodium Di(2-Ethylhex.yl)

Suliosuccinate 2.3 3.8 600 3.3 600 1 Ester of CHaCHOHCeHrx neutral, acid and alkaline solution at 25 C., and again 5 that the wetting time at 0.10% concentration is reduced after heating in acid and alkaline solution at 100 C. for a specified time, cooling and re-determining the wetting time.

The sulfosuccinate lost all {wetting properties after by decreasing the concentration to 0.05 and adding builder. Thus wetting time values of 13.2, 33.1 and 103.0 seconds are reduced to 5.0, 13.6 and 43.3 seconds, respectively even though only half as much wetting agent heating in either acid or alkaline solution. The sodium is used.

WVETTING TIME,

SHOWN, BUILT AND UNBUILT, IN SOFT AND HARD 'lWATER Distilled Hard Water, 300 p.p.m.

Water RCH(SO3N3)CO2R' Unbuilt Built l 0.05, 0.10, 0.05, 0.10, 0.05, 0.01, Percent Percent Percent Percent +0.2B, +0.4B,

Percent Percent Na. Octyl a-Suliopelargonate I-.." 5.0 1 3 21. 2 13. 2 5.0 4. 0 Na Nonyl msuliopelargonateufl- 8. 8 3 8 40. 8 33. 1 13. 6 8. 2 Na Decyl a-Sulfopelargonate 24.8 6 0 130.0 105. 0 43. 3 31. 6 Na Salt of 2Ethylhexyl Ester oi a-Sulfo Coconut Oil Fatty Acid Forerun II 10. 8 3. 5 40. 2 7. 0 16. 2 6.0 Na Methyl a-Sultostearate III 59.0 46. 6 300 91. 0 58. 8 59. 5 Na Isopropyl a-Sulfostearate IV-. 84. 0 82. 0 163.0 68. 3 100.0 58. 4 Mixtures:

0.05% I+0.05% III 9. 5 10.0 8.0 0.05% I+0.05% IV. 9. 0 10. 0 10. 0 0.05% II+0.05% III 12. 7 l4. 6 14. 3

1 Builder, B, has the composition 56% sodium tripolyphosphate, 24% sodium sulfate, 10% sodium pyrophosphate and 10% sodium metasilicate.

synergism in mixtures of the wetting agents of our invention with sodium alkyl a-sulfopalmitates and sodium alkyl a-sulfostearates is shown in Table VI. Thus in distilled water a mixture of 0.05% 14-0105 III has a wetting time (9.5 seconds) less than the sum of the wetting times for 0.05% I and 0.05% II alone (64.0 seconds), and less than the average of the sums for 0.10% I and 0.10% III alone (24.0 seconds). Like synergism in distilled Water solution is shown for mixtures of I with IV and mixtures of II with III. Synergism is also shown for each of the mixtures in solutions in hard Water and for solutions in hard water in the presence of builder.

Sodium alkyl u-sulfopalmitates and sodium salts of alkyl esters of a-sulfonated hydrogenated tallow acids are also synergistic in wetting properties with the wetting agents of our invention.

DETERGENT COMPOSITIONS The data of Table VII show that the 'wetting agents of our invention have good detergent properties in hard and moderately hard water in the presence of builder, and can also :be used in built detergent compositions with soap and with sodium salts of et-sulfonated hydrogenated tallow acids, as typified by sodium methyl a-sulfostearate. The builder used is that of Table VI. For comparison the AR values for 0.25% sodium dodecyl sulfate are 21 and 24 in 150 and 300 p.p.m., respectively.

TABLE VII Detergent Compositions 1 Increase in reflectance after washing.

We claim:

1. A compound of the formula RCH(SO M)COOR' where R is an n-alkyl group containing from 2 to 12 carbon atoms, inclusive, M is selected from the group consisting of sodium, potassium and ammonium, R is a radical selected from the group consisting of dodecafluoroheptyl and a straight and branched chain alkyl radical containing from 2 to 12 carbon atoms, inclusive, and the sum of the carbon atoms in R plus R plus 2 is an integer from 14 to 19, inclusive.

2. Sodium dodecyl ot-sulfobutyrate.

3. A compound of the formula of claim 1 in which R is the n-heptyl radical.

4. Sodium n-hexyl u-sulfopelargonate.

5. Sodium n-heptyl a-sulfopelargonate.

6. Sodium capryl a-sulfopelargonate.

7. Sodium 2-ethylhexyl a-sulfopelargonate.

8. Sodium dodecafluoroheptyl a-sulfopelargonate.

9. A compound of the formula of claim 1 in which R is CH3(CH2)9 10. Sodium ethyl ot-sulfolaurate.

11. Sodium propyl a-sulfolaurate.

12. Sodium butyl u-sulfolaurate.

13. Sodium amyl a-sulfolaurate.

14. Sodium hexyl u-sulfolaurate.

15. A compound of the formula of claim 1 in which R iS CH3(CH2)11.

16. Potassium butyl a-sulfomyristate.

Weil et al.: J. Am. Chem. Soc. 75, pp. 48594860 (1953).

Weil et al.: I. Am. Oil Chemists Soc. 37, pp 679-682 (1960). 

1. A COMPOSITION OF THE FORMULA RCH(SO3M)COOR'' WHERE R IS AN N-ALKYL GROUP CONTAINING FROM 2 TO 12 CARBON ATOMS, INCLUSIVE, M IS SELECTED FROM THE GROUP CONSISTING OF SODIUM, POTASSIUM AND AMMONIUM, R'' IS A RADICAL SELECTED FROM THE GROUP CONSISTING OF DODECFLUOROHEPTYL AND A STRAIGHT AND BRANCHED CHAIN ALKYL RADICAL CONTAINING FROM 2 TO 12 CARBON ATOMS, INCLUSIVE, AND THE SUM OF THE CARBON ATOMS IN R PLUS R'' PLUS 2 IS AN INTEGER FROM 14 TO 19, INCLUSIVE. 